Improper frame handling in the Zyxel XGS2220-30 firmware version V4.80(ABXN.1), XMG1930-30 firmware version V4.80(ACAR.1), and XS1930-10 firmware version V4.80(ABQE.1) could allow an unauthenticated LAN-based attacker to cause denial-of-service (DoS) conditions by sending crafted frames to an affected switch.

An improper check for unusual or exceptional conditions in the HTTP request processing function of Zyxel GS1920-24v2 firmware prior to V4.70(ABMH.8)C0, which could allow an unauthenticated attacker to corrupt the contents of the memory and result in a denial-of-service (DoS) condition on a vulnerable device.